If you could create a unique GM Event/Reward...

[Whirled]

Some great ideas ^ ^ ^

Did they ever make a Mummy illusion item? That'd be pretty cool having Rabies proc

[Lhancelot]

Potion of Randomness. This potion would alter the race, sex, or deity OR all three permanently when consumed by the character.

[Rygar]

The Purge: Norrath Edition

Full PvP enabled, PvP death creates exp loss (albeit more minor), PvP kills give you +faction with something like ThePurge, death gives you -faction hit (system enabled so you can't kill the same person over and over or somehow game the system with a group of buddies). All server rules suspended (raid policy, ninja looting, training, etc).

Every mob in world is KoS and on same social faction (bankers, merchants, quest givers, etc). Only Bristlebane who appeared on the Butcherblock Chessboard is non-KoS. Bristlebane announces bounties on people via global message every 15 minutes, kills on those players named give additional faction boosts, players with bounty on their head gets additional faction for everyone they kill. Max-Ally faction after purging is needed for a quest chain.

Gather the blood of every town leader and return it to Bristlebane. Completing the quest ends the Purge, the reward:
1) You earn the title 'The Hated One'
2) 1ac helmet, the graphic just looks like Bristlebane's entire head on your body
3) Every faction in Norrath goes to max KoS for you
4) All participants that logged over 300 units of faction hits suffer -300 faction hit to all factions across Norrath

[Brut]

Couple days long event of Bristlebane teleporting around Norrath having a random chance of having his model on different named dungeon bosses, having a buffed hp bar, some halfling illusion proc ability and the usual classic god ae dispel gflux, dropping tons of consumable illusion items and whatnot (chance of guises I guess). Or just any NPC anywhere pretty much, just give people incentive to look around Norrath then notice "oh wtf this random Erudin Palace guard is Bristlebane!". Occasionally spawns as a raid target with the same alterations. Just random surprise Gorenaire roaming around Dreadlands but with huge Bristlebane model. Add goofy dialogue.

Final battle days later as a GM event in his throne room at PoMischief to put a stop to his shenanigans.

[Baler]

Monster Bash - Players are put into a pen with monster(s) and are forced to beat said monster or die. After monster(s) are killed, players are healed and a stronger monster(s) are put in the pen for them to defeat. Last man/woman/thing standing wins.

Town Invasion - Monsters are going to attack a city, town or area. Players must defend against the invasion which all climaxes at a final boss beyond an army of monsters.

PVP (1v1s / 2v2s) - Players are placed in an arena and must fight one another to the death. Matches take place until the final player/duo is victorious.

Capture The Flag (team(s) vs team(s)) - must capture the enemies flag/item and deliver it to their home base for points.

Scavenger hunt - items of a defined type are spawned across the world. Players all start in a general location and must search the world for said items. There is a time limit the people with the mobs of these items get prizes for 1st, 2nd and third.

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Just a few, going to stop here for now. Ultima Online has done a vast amount of various events in the past. Most of my ideas stem from there. Could fill pages of this thread with ideas.

[xtraball]

The Killing Spree : Everybody is IN-VUL-NE-RA-BLE for 30 minutes. Exp is doubled. No loot.

[Amyas]

Race/god change pot

[xtraball]

The Race :
Going from Freeport Arena to Prince's Room in the Warrens, no SOW or JBoots, no port. First to arrive wins. Only untwinked lv 1 toons. Special reward for the fastest highest and the fastest lowest leveler.

[xtraball]

The ultimate EQ reward : have a NPC named after the winner and placed wherever he sees fit.

[xtraball]

Humans vs Zombies :
Two teams, each contestant is either a lv 1 human warrior or a zombie/decaying skel/whatever low level undead being.
Last man/undead standing wins !